Synthetic peptide antigens are of interest for use in vaccines to prevent infectious diseases (such as viral, bacterial, parasitic and fungal infections). Synthetic peptide antigens are also of interest in the field of immunotherapeutics, including the treatment of infection, the stimulation of immunity to cancer cells, the down-regulation of polypeptide hormones and the control of inappropriate immune responses such as anaphylaxis and allergy.
One difficulty in the practical use of peptide-based vaccines and immunotherapies is ensuring the induction of an immune response by efficient delivery of the peptide antigens to an antigen presenting cell. Without such targeting, unfeasible amounts of the peptide may be required, which would not only be uneconomical to manufacture but could also lead to toxicity issues.
Enhancement of peptide delivery may be achieved through specialised delivery vehicles, such as particulate-based structures enabling sustained release. In addition, peptide derivatives or modified peptides comprising the peptide of interest covalently linked to a delivery-enhancing agent have been developed to improve the bio-availability and presentation of the peptide to specific target cells and receptors.
One particular class of peptides modified to improve delivery to antigen presenting cells are constructed through the covalent attachment of a fluorocarbon chain to either the peptide N- or C-terminus, or at any position in between, to create a fluorocarbon-linked peptide (FCP). Examples of fluorocarbon-linked peptides are given in WO2005/099752 and WO2009/027688 and the advantages afforded by the fluorocarbon attachment in the enhancement of immune responses to the peptide are provided therein.
It will be understood by vaccine designers that more than one peptide may be required to provide a broader prophylactic or immunotherapeutic effect. Such multi-component products are desirable since they are likely to be more effective at eliciting appropriate immune responses.
In order to manufacture a pharmaceutical product of this nature, the fluorocarbon-linked peptides must be synthesised, purified, blended together at appropriate ratios, rendered sterile and presented in a homogenous format suitable for administration.